An influential politician who’s actually an enemy mole, turned while a prisoner of war, and now subverting America ... It’s the subject of Homeland, the hit cable series. Ironically, the program’s second season on Showtime unfolds exactly 50 years after a classic movie first named its theme.

The Manchurian Candidate premiered in October 1962. Since then the specific strain of ideological corruption has mutated, from communism to violent Jihadism, but the public remains fascinated with the concept of brainwashing – of Americans returning from captivity secretly beholden to foreign enemies. Now U.S. government records, many declassified after decades of secrecy, are finally revealing the real story behind the enduring meme.

The records describe Chinese spymasters assigning intelligence and propaganda missions to returning U.S. POWs and sending them home to a Soviet-linked support network of collaborators from Middle America to Eastern Europe.

Told to expect contact once back in America, the men were to “lay low for two or three years,” and “prepare the way in the United States for progressives to come later,” Army intelligence reported. Unlike the enemy’s robotic control of The Manchurian Candidate, influence over these real “Candidates” was much closer to the indoctrination and blackmail of Homeland. As to the ultimate effectiveness and extent of the program, much remains unknown. Just last year, the National Archives removed 60-year-old documents on this topic from public view, saying they’re still classified or may have “law enforcement sensitivities.” The CIA will not even confirm or deny it has such records. What has been uncovered tells a chilling tale, indicating reality was sometimes more disturbing than fiction. For example, the communists kept certain American prisoners forever to facilitate Soviet espionage and Cold War plotting, according to declassified files.

Brainwashing first gripped the national imagination during the Korean War from 1950-53, which pitted the United States, South Korea and their United Nations allies against North Korea and China, backed by the Soviet Union. For most of the war, Chinese commissars, working with Soviet advisors, controlled the publicly-known prison camps for Americans in North Korea, along with secret camps U.S. intelligence believed existed in China.

While many American prisoners in Korea behaved with distinction under appalling conditions, a large number collaborated with the enemy by informing on their fellows, writing propaganda statements and making detailed false confessions, including to germ warfare. Twenty-one of them, the so-called “Turncoats,” even chose to live in China after the war. These actions provided crucial ammunition to the “Hate America” campaign, as the Eisenhower White House called it, an orchestrated, high-stakes propaganda offensive then being waged by Moscow from the Third World to the United Nations.

At the time, military intelligence and the CIA scrambled to understand what could motivate American fighting men to turn on their country. Brainwashing appeared one possibility. The CIA launched its own mind-control experiments (ironically, these eventually involved more injurious techniques than many used by the enemy in Korea).

Hard answers finally arrived with the thousands of surviving Americans released from enemy camps in 1953. The Pentagon was ready with programs to interrogate and process the men, including the Army’s “RECAP-K” project (for men “recaptured” from Korea; the similar RECAP-WW project was soon added for the surprisingly large number of U.S. troops worldwide who - by defection, abduction or drunken escapade – landed in Soviet-bloc countries during the Cold War.)

Part of the plan was to root out prisoners “turned” by the enemy. Floating interrogations began on a troop ship headed home to the States. So-called “Progressives” (also known as “Pro’s,” or by the Chinese, “Good Students”) from the prison camps received most attention. Known collaborators, the Progressives had cooperated with their guards, sometimes at the cost of beatings from secret groups of anti-communist prisoners, known as “Reactionaries” (reactionary groups had their own nicknames, such as the “KTC" (Kill the Communists); “Federated American Hearts,” and “KKK.”) Thrashings of progressives actually continued on the troop ship; with no Chinese guards to protect them, some collaborators had to be segregated for their own safety.

Evidence from the returning Americans, according to intelligence reports and congressional hearings, disproved popular, and perhaps even hopeful, speculation about the motives for collaboration. The prisoners had not been drugged and brainwashed with secret, irresistible techniques. They were never under absolute psychological control of their captors. No secret triggers put them into a trance, such as the famous Queen of Diamonds in The Manchurian Candidate. In short, these troops had not been “brainwashed.”

Instead they had been subjected to the type of comprehensive indoctrination routinely employed by Soviet and Chinese officials against their own dissidents, along with German and Japanese POWs from World War II. The methods included isolation; sleep deprivation; compulsory ideological classes; threats; public- and self-criticism; endless “confessions;” exploitation of anger over U.S. racial discrimination; destruction of the chain of command; sophisticated psychological pressure; bribery and blackmail.

Still, as Homeland dramatizes, brainwashing is not necessary to produce spies – indoctrination and blackmail are quite sufficient. U.S. military intelligence certainly understood this in 1953 and eventually confirmed that some returned Progressives had indeed received missions from their captors. A soldier we’ll call “Corp. C.” admitted that in North Korea he “accepted an espionage mission in the United States, and in preparation therefor, accepted training and instruction in the espionage service of the Chinese Communist Government …,” a now-declassified intelligence file reported (Because people mentioned in the declassified documents may still be alive, their names are redacted here.)

Remarkably, after coming under scrutiny, Corp. C. legally registered as an official “foreign agent,” apparently to avoid penalties against unregistered agents. The Army had the registration yanked from public examination in the “interest of national security” (we could not determine which country Corp. C represented, presumably China or the Soviet Union.) A returned prisoner of Filipino descent, the files said, had been ordered to conduct espionage, including recruiting agents, first in the Philippines and then Indonesia. The intent of another returnee, “Corp. S.,” was “to commit sabotage against the U.S.” and overthrow the government.

Awaiting their homecoming in America was a network of sympathizers and friendly organizations. The CPUSA, or Communist Party USA, was to keep the men under surveillance, according to one report (a separate file shows the name, address and phone number of a returnee was found in possession of a “known (civilian) communist” named “M.G.”) Some returnees were to report for membership in the Party. New York’s Jefferson School of Social Sciences, a large left-wing academic institution, was recommended as a place to study. More ominously, “Soldier H.” confessed he and others were told to join the Save Our Sons (SOS) Committee, an Illinois-based group claiming to represent families of GIs in POW camps and on the battlefield. Said to reach 17 states and send information to 3,000 parents of imprisoned servicemen, the group also petitioned the President and members of Congress.

The Chairman of SOS, "Mrs. G.," had a son-in-law wounded in the war. But the son-in-law did not support the group, an FBI informant close to the group later testified to Congress in 1956, reporting Mrs. G. had been an active member of the Communist Party long before the war and subsequent launch of SOS.

SOS was well known to U.S. POWs in North Korea, returned prisoner Dale Jones testified in that 1956 congressional hearing. The Chinese even suggested Jones sign an SOS petition to avoid punishment for getting in a fight. “Well, they used to ask us to do things like that. They told us that we weren't forced to do nothing like that, but we were in no position to refuse,” he told a questioner. “Well, it meant just that – if you did go against them and refused them a lot of times, be reactionary (note: resistant or pro-American) toward them, you might just some night disappear out of the camp, like a lot of boys did.” (For information on such disappearances, like that of Sgt. Richard Desautels, spirited away to China from a Korean prison camp and never returned, see www.kpows.com)

Back at home, apparently unknown to Jones in his frigid hovel thousands of miles away, SOS distributed a letter it claimed was written by him. Like many of the group’s communications, the screed echoed communist negotiating points. It read in part: “Thousands of people are dying just because there are a few individuals who want a little more for themselves. … (I)t is up to all the peace-loving people of the world to make more and more people see how they are being fooled by these handful (sic) of profit-makers …” Once home, Jones denied before Congress that he had penned the missive. Such bombast did seem unlikely from a soldier with just an eighth-grade education, one congressman concluded sympathetically.

Faced during the hearing with questions about this letter and the group’s operations and finances, Mrs. G. and SOS’s treasurer took the Fifth repeatedly.

The U.S. Postal Service was also a cruel tool for other people and groups - some apparently part of a shadowy network - that contacted relatives of missing and imprisoned GIs. An FBI official at the time described such letters to family members as “exploiting them for information, propaganda, or money.” In some cases, mysterious correspondence arrived from abroad, including Czechoslovakia, a close Soviet ally with a presence in North Korea. Many others were sent from inside America. Aside from political points, the correspondence sometimes implied that contacting a certain foreign address or sending money to the letter writer’s organization might lead to information about a missing loved one, or better treatment for a known POW, said reports at the time. We found evidence of such letters being sent long after the war. Aside from propaganda and fund-raising (probably including scams by common crooks), the letter campaigns may have advanced intelligence-gathering objectives still unknown.

Meanwhile, Army intelligence was running its own Top Secret operation involving mail, this one to intercept and withhold certain correspondence home from American prisoners in Korea. Letters from “PFC S.” were held back “because of evidence of collaboration and the fact that his parents, active in Communist movements on the West Coast, use material furnished by him in making additional contacts and spreading Communist propaganda,” revealed a document from the program.

The exact size, extent and duration of Moscow and Beijing’s Korean War POW espionage operations, and America’s response, remain unknown. Although a 1950s media report claimed up to 75 returned prisoners were espionage agents, declassified files show the actual number of detected operatives was much lower. Right after the war, military officials and the FBI were surprisingly lenient with these suspects and other collaborators, perhaps because a segment of public opinion opposed vigorous prosecution of servicemen who, despite their potential crimes, had certainly suffered during captivity. This somewhat relaxed attitude changed briefly in 1959 when the House Un-American Activities Committee asked the Army for detailed information on returned spies. Bureaucratic alarm ensued as Army officials reviewed their files and the effectiveness of their coordination with the FBI, which assumed jurisdiction over returnees once they left the military.

Documents from this review show the focus remained on Progressives, many from the same North Korean prison camp. They were generally lower-ranking Army enlisted men whose wartime cooperation with camp officials had been blatant, such as making propaganda statements or acting as leaders in communist activities. Some had spent time alone with top Chinese commissars. Our review of internal Army suspect files found the “short lists” had relatively few officers and were surprisingly lacking in men who seemed destined for high or sensitive positions. None of them appeared to be a “Raymond Shaw,” the politically-connected POW in The Manchurian Candidate, or a ranking official of the importance and prospects of England’s George Blake.

Had the communists restricted their elaborately planned recruiting efforts only to known Progressives, who aside from their generally low positions and weak personalities were also the most obvious targets for U.S. spy hunters? Not likely. An Army intelligence expert on the POW issue was quoted as saying that some Reactionaries, or pro-Americans, had missing time (our term) in their histories of captivity. He asserted they had been removed from the regular prisoner population, indoctrinated and given intelligence training, and then returned - so their fellow prisoners and U.S. intelligence would never suspect them.

Another source of potential low-profile, high-quality spies was the population of American prisoners who never returned from captivity (other than the 21 known U.S. "turncoats" remaining in China). Among some 8,000 American POW/MIAs who did not return from Korea, intelligence reports indicated, were men secretly held in China and the Soviet Union. The reported motive: Exploitation for espionage, propaganda, intelligence and even technical and unskilled labor. The Soviets, whose fighter pilots downed many Americans during the Korean War, viewed all-out war with the U.S. as a real possibility, so captured pilots and other experts on U.S. weapons and technology had great value. Other Americans might be assigned to “high-level propaganda purposes” such as establishment of an “American Government in Exile,” reported one military intelligence report. (When the Korean War started, the Soviets already had a sophisticated, nation-wide program to use foreign POWs for propaganda, technology development and spying – it was then focused on German and Japanese prisoners from WWII.)

The Korean War created a windfall of both U.S. and allied prisoners to feed the voracious appetite of the Soviets and their Chinese partners for information and agents from Western adversaries. Some prisoners, according to a report from an elite U.S. unit, were quickly dispatched to “be specifically trained at Moscow for intelligence work. PWs transferred to Moscow are grouped as follows: British 5, Americans 10, Canadians 3, and 50 more from various countries.” This report, if true, seems to involve different Englishmen than the notorious British intelligence officer George Blake, whose case does not fit these details. Blake, serving in Korea when captured, responded to indoctrination by becoming an enthusiastic communist. Released at the end of the war, Blake began to spy for the Soviets, becoming one of Britain’s most infamous double agents.

The case of Gerald W. Glasser, a soldier from Pennsylvania, represents the level of intrigue and tragedy in the communist prison system. At the end of the war Glasser was healthy and living in POW Camp Number 1, at Chang-Song, North Korea. One day Chinese officers in a jeep showed up and took him away. “(T)here was nothing to indicate his removal from camp was in the nature of an arrest as he and his camp companions were given candy and cigarettes before leaving,” according to Army intelligence. Glasser was not repatriated at the end of the war.

But was the man removed from Camp Number 1 actually Gerald Glasser? Another record we obtained includes information from one of Glasser’s fellow prisoners. A US intelligence official, said the former prisoner, told him: “He (Glasser) as we knew him was not really Gerald Glasser.” The official claimed Glasser was killed when captured and a Russian agent took his identify to spy on American prisoners.

The infiltration of prison populations and use of false identifies were common enough for Russian intelligence. But Glasser’s family reported getting friendly letters home from him during the war. Were the letters fake? Or was Glasser alive in a separate camp from his doppelganger, perhaps never knowing his identify was in use? Or was the whole impersonation story false? Only the Chinese and Russians know for sure, and they still refuse to tell. All we know for sure is that Gerald Glasser has never come home.

“The (U.S.) POW’s will be screened by the Soviets and trained to be illegal residents (spies) in U.S. or other countries where they can live as Americans,” reported a White House document based on information from a controversial KGB defector (see this original document and others at: www.koreanconfidential.com). Biographies of dead Americans would be used to create “legends” (cover stories) for Soviet spies, said the memo, and “selected POW’s” will be used for propaganda work.

“It follows that the Communists would neither wish to return these men to U.S. control nor admit to their existence at this time,” concluded the military intelligence report about high-level propaganda mentioned above. Such fears appeared to be realized at the end of the war, when the State Department alerted U.S. embassies across the world that some American prisoners would likely be kept by the enemy. A year later, according to a newly revealed 1954 document, Air Force Chief of Staff Gen. Nathan Twining requested covert C.I.A. assistance to recover “an unknown but apparently substantial number of U. S. military personnel captured in the course of the Korean War (who) are still being held prisoners by the Communist Forces.”

Soon after, the U.S. Embassy in Moscow delivered a note to the Soviet government asking it “to arrange their (U.S. POWs taken from Korea to the Soviet Union) repatriation at the earliest possible time.” The Soviets responded by denying they had the prisoners. By 1955, the Pentagon had apparently given up hope of recovering the men, according to a then-classified memo: “The problem becomes almost a philosophical one. If we are ‘at war,’ cold, hot or otherwise, casualties and losses must be expected and perhaps we must learn to live with this sort of thing. If we are in for 50 years of peripheral ‘fire fights’ we may be forced to adopt a rather cynical attitude on this (the POWs) for the political reasons.”

In the decades since, most U.S. efforts to trace these lost Americans have been blocked by the Russian, Chinese and North Korean regimes, along - say many POW/MIA family members - with U.S. government bureaucratic indifference and secrecy. Some important exceptions, such as a now-stopped US investigation in the former Soviet-bloc, have uncovered more evidence the Americans were kept, and prove Moscow, Beijing and Pyongyang are still hiding the truth about these lost American heroes.

Open questions also include communist exploitation of American prisoners in other conflicts. During the Cold War, Lee Harvey Oswald, a former Marine back in America after defecting to the Soviet Union, killed President Kennedy – just a year after The Manchurian Candidate was released. Investigators ultimately excluded Soviet involvement in that crime. Scores of active-duty U.S. servicemen ended up in communist hands during the Cold War; RECAP-WW and other files on many of them have now been released. But a full account from the Vietnam War will likely prove impossible, since 1990s legislation, popularly known as the “McCain Truth Bill,” actually bars researchers from certain types of information available on earlier conflicts.

From our most recent wars, the only US POW now confirmed alive in enemy hands is Army Sgt. Bowe Bergdahl, held in Afghanistan since 2009. Public accounts, video of his captivity and the historic behavior of Afghan hostage takers suggest it unlikely Sgt. Bergdahl is being prepared for the high intrigue of Homeland, The Manchurian Candidate, or the Chinese intelligence service. Despite the grim history described above, one wonders if a heated Chinese propaganda classroom might look almost tolerable to Sgt. Bergdahl about now.

Korean Confidential is produced by Mark Sauter, an investigative historian. A corporate strategy advisor and former investigative correspondent for national television programs, Sauter has been pursuing the fate of U.S. POWs from the Korean War and other mysteries related to North Korea for more than 20 years. He has conducted research in North Korea, Russia and the U.S. National Archives. A volunteer researcher for POW/MIA family groups, he commanded a guard post in the Korean Demilitarized Zone while an Army officer in the 1980s. Sauter is co-author of Homeland Security: a Complete Guide, the McGraw-Hill university textbook.